Most cultures of the world have believed that at least 90 percent of the universe is essentially non-visible. Contemporary physicists readily admit that they rarely see what they study. Rather, like the search for Big Foot’s footprints, they can only employ outrageously complex technological devices to illustrate the evidence that elementary particles of reality have previously been where they can no longer be seen to exist. Zen art (like some the of the best western conceptual art) was devoted to invoking a similarly non-material reality. Zen potters have always been interested in the human experience of what they understood as more than visible, just as western conceptual artists are interested in the non-commodity aspect of art. For Zen practitioners it is what they call the essence or spirit of a moment in time/space that is of value...Janis Runge